As a new B14R owner I've read about the inability of the current rifles to accept the very nice and readily available Vudoo 10 round polymer mags.
They apparently work for a few and absolutely do not work for others. Anecdotally it seems like the newer rifles do not allow them to work as manufactured.
Figured I'd give it a shot and order a three pack of Vudoo mags to mod. If I ruined them I wasn't going to be too upset. Impression upon receipt was they have a substantially better build quality and are overall a much more solid mag that reminds me of the Smith & Wesson MP22 mags, very nice.
The mags locked in to what appeared an appropriate depth and fit in my B14R action in a Cadex Strike Nuke Evo chassis. The bolt was open when I inserted the mag. Upon bolt close attempt, the bolt stopped forward motion within millimeters. Looking in the receiver it was apparent that the aft, left corner of the magazine feed lip was in contact with the ejector.
My first attempt was to file a bit from the rear bolt catch on the magazine in an effort to reduce the feed lip overall height relative to the action. After pulling a few millimeters off it would cycle but the angle was now incorrect and it would not feed, it would lock up the bolt/dummy round when the round tried to enter the chamber at too steep an angle. I used two part Apoxie black sculpting epoxy to recreate the missing magazine latch ledge material and let it cure until morning.
The next approach was to just remove material from the mag in the vicinity of the offending rifle ejector. I noticed when the Vudoo mag was inserted it would kick the ejector up just enough to prevent bolt forward motion. See below for ejector location and empty/mag inserted action views. Pardon the plastic dust in the action making it look like I am a nasty slob that never cleans his hardware, it was taken during this mag mod filing work.
I started slowly filing material away to create a small notch and radius on that back left corner to clear the ejector. Within a few minutes the mag would not only seat but I could run the bolt although it was a bit difficult to get the initial motion.
A few more minutes of filing to remove material and it worked. The bolt moved freely, the mag no longer contacted the ejector and I was able to feed, cycle and eject 10 A-zoom snap cap dummy rounds continuously with no issues.
I replicated that same change on a second Vudoo mag is a test and once again it allowed the Vudoo mag to seat properly and feed perfectly. Shown below is the modified mag. The best solution would be to cleanly mill out the required notch but this works and is simple to do.
Not saying this alone will work for every rifle and chassis set up (mag latch height could be another issue depending on chassis latch geometry/action relation) but I would imagine this addresses the primary reason Vudoo mags won't work out of the box in most B14R rifles.
With this simple mod you should be able to run these awesome mags. I would even be interested to see if a modded mag makes any difference ina Vudoo action, my guess is that it would not and they would run just fine in a Vudoo as well.